added alg_sort.c
This commit is contained in:
parent
43bc5ffb79
commit
70f0002cea
321
qse/lib/cmn/alg_sort.c
Normal file
321
qse/lib/cmn/alg_sort.c
Normal file
@ -0,0 +1,321 @@
|
||||
/*
|
||||
* $Id$
|
||||
*
|
||||
Copyright 2006-2009 Chung, Hyung-Hwan.
|
||||
This file is part of QSE.
|
||||
|
||||
QSE is free software: you can redistribute it and/or modify
|
||||
it under the terms of the GNU Lesser General Public License as
|
||||
published by the Free Software Foundation, either version 3 of
|
||||
the License, or (at your option) any later version.
|
||||
|
||||
QSE is distributed in the hope that it will be useful,
|
||||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
GNU Lesser General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU Lesser General Public
|
||||
License along with QSE. If not, see <http://www.gnu.org/licenses/>.
|
||||
*/
|
||||
|
||||
/*-
|
||||
* Copyright (c) 1992, 1993
|
||||
* The Regents of the University of California. All rights reserved.
|
||||
*
|
||||
* Redistribution and use in source and binary forms, with or without
|
||||
* modification, are permitted provided that the following conditions
|
||||
* are met:
|
||||
* 1. Redistributions of source code must retain the above copyright
|
||||
* notice, this list of conditions and the following disclaimer.
|
||||
* 2. Redistributions in binary form must reproduce the above copyright
|
||||
* notice, this list of conditions and the following disclaimer in the
|
||||
* documentation and/or other materials provided with the distribution.
|
||||
* 3. Neither the name of the University nor the names of its contributors
|
||||
* may be used to endorse or promote products derived from this software
|
||||
* without specific prior written permission.
|
||||
*
|
||||
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
||||
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
||||
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
||||
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
||||
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
||||
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
||||
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
||||
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
||||
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
||||
* SUCH DAMAGE.
|
||||
*/
|
||||
|
||||
#include <qse/cmn/alg.h>
|
||||
|
||||
#define qsort_min(a,b) (((a)<(b))? a: b)
|
||||
|
||||
/*
|
||||
* Qsort routine from Bentley & McIlroy's "Engineering a Sort Function".
|
||||
*/
|
||||
#define swapcode(TYPE,parmi,parmj,n) { \
|
||||
qse_size_t i = (n) / sizeof (TYPE); \
|
||||
register TYPE *pi = (TYPE*)(parmi); \
|
||||
register TYPE *pj = (TYPE*)(parmj); \
|
||||
do { \
|
||||
register TYPE t = *pi; \
|
||||
*pi++ = *pj; \
|
||||
*pj++ = t; \
|
||||
} while (--i > 0); \
|
||||
}
|
||||
|
||||
#define SWAPINIT(a,size) \
|
||||
swaptype = ((qse_byte_t*)a-(qse_byte_t*)0)%sizeof(long) || \
|
||||
size % sizeof(long) ? 2 : size == sizeof(long)? 0 : 1;
|
||||
|
||||
static QSE_INLINE void swapfunc (
|
||||
qse_byte_t* a, qse_byte_t* b, int n, int swaptype)
|
||||
{
|
||||
if (swaptype <= 1)
|
||||
swapcode(long, a, b, n)
|
||||
else
|
||||
swapcode(qse_byte_t, a, b, n)
|
||||
}
|
||||
|
||||
#define swap(a, b) \
|
||||
if (swaptype == 0) { \
|
||||
long t = *(long*)(a); \
|
||||
*(long*)(a) = *(long*)(b); \
|
||||
*(long*)(b) = t; \
|
||||
} else swapfunc(a, b, size, swaptype)
|
||||
|
||||
#define vecswap(a,b,n) if ((n) > 0) swapfunc(a, b, n, swaptype)
|
||||
|
||||
static QSE_INLINE qse_byte_t* med3 (
|
||||
qse_byte_t* a, qse_byte_t* b, qse_byte_t* c,
|
||||
qse_sort_comper_t comper, void* ctx)
|
||||
{
|
||||
if (comper(a, b, ctx) < 0)
|
||||
{
|
||||
if (comper(b, c, ctx) < 0) return b;
|
||||
return (comper(a, c, ctx) < 0)? c: a;
|
||||
}
|
||||
else
|
||||
{
|
||||
if (comper(b, c, ctx) > 0) return b;
|
||||
return (comper(a, c, ctx) > 0)? c: a;
|
||||
}
|
||||
}
|
||||
|
||||
void qse_qsort (
|
||||
void* base, qse_size_t nmemb, qse_size_t size,
|
||||
qse_sort_comper_t comper, void* ctx)
|
||||
{
|
||||
qse_byte_t*pa, *pb, *pc, *pd, *pl, *pm, *pn;
|
||||
int swaptype, swap_cnt;
|
||||
long r;
|
||||
qse_size_t d;
|
||||
register qse_byte_t*a = (qse_byte_t*)base;
|
||||
|
||||
loop:
|
||||
SWAPINIT(a, size);
|
||||
|
||||
swap_cnt = 0;
|
||||
if (nmemb < 7)
|
||||
{
|
||||
for (pm = (qse_byte_t*)a + size;
|
||||
pm < (qse_byte_t*) a + nmemb * size; pm += size)
|
||||
{
|
||||
for (pl = pm; pl > (qse_byte_t*)a &&
|
||||
comper(pl - size, pl, ctx) > 0; pl -= size)
|
||||
{
|
||||
swap(pl, pl - size);
|
||||
}
|
||||
}
|
||||
return;
|
||||
}
|
||||
pm = (qse_byte_t*)a + (nmemb / 2) * size;
|
||||
if (nmemb > 7)
|
||||
{
|
||||
pl = (qse_byte_t*)a;
|
||||
pn = (qse_byte_t*)a + (nmemb - 1) * size;
|
||||
if (nmemb > 40)
|
||||
{
|
||||
d = (nmemb / 8) * size;
|
||||
pl = med3(pl, pl + d, pl + 2 * d, comper, ctx);
|
||||
pm = med3(pm - d, pm, pm + d, comper, ctx);
|
||||
pn = med3(pn - 2 * d, pn - d, pn, comper, ctx);
|
||||
}
|
||||
pm = med3(pl, pm, pn, comper, ctx);
|
||||
}
|
||||
swap(a, pm);
|
||||
pa = pb = (qse_byte_t*)a + size;
|
||||
|
||||
pc = pd = (qse_byte_t*)a + (nmemb - 1) * size;
|
||||
for (;;)
|
||||
{
|
||||
while (pb <= pc && (r = comper(pb, a, ctx)) <= 0)
|
||||
{
|
||||
if (r == 0)
|
||||
{
|
||||
swap_cnt = 1;
|
||||
swap(pa, pb);
|
||||
pa += size;
|
||||
}
|
||||
pb += size;
|
||||
}
|
||||
while (pb <= pc && (r = comper(pc, a, ctx)) >= 0)
|
||||
{
|
||||
if (r == 0)
|
||||
{
|
||||
swap_cnt = 1;
|
||||
swap(pc, pd);
|
||||
pd -= size;
|
||||
}
|
||||
pc -= size;
|
||||
}
|
||||
if (pb > pc) break;
|
||||
swap (pb, pc);
|
||||
swap_cnt = 1;
|
||||
pb += size;
|
||||
pc -= size;
|
||||
}
|
||||
|
||||
if (swap_cnt == 0)
|
||||
{
|
||||
/* switch to insertion sort */
|
||||
for (pm = (qse_byte_t*)a + size;
|
||||
pm < (qse_byte_t*)a + nmemb * size; pm += size)
|
||||
{
|
||||
for (pl = pm; pl > (qse_byte_t*)a &&
|
||||
comper(pl - size, pl, ctx) > 0; pl -= size)
|
||||
{
|
||||
swap(pl, pl - size);
|
||||
}
|
||||
}
|
||||
return;
|
||||
}
|
||||
|
||||
pn = (qse_byte_t*)a + nmemb * size;
|
||||
r = qsort_min(pa - (qse_byte_t*)a, pb - pa);
|
||||
vecswap (a, pb - r, r);
|
||||
r = qsort_min (pd - pc, pn - pd - size);
|
||||
vecswap (pb, pn - r, r);
|
||||
|
||||
if ((r = pb - pa) > size) qse_qsort(a, r / size, size, comper, ctx);
|
||||
|
||||
if ((r = pd - pc) > size)
|
||||
{
|
||||
/* Iterate rather than recurse to save stack space */
|
||||
a = pn - r;
|
||||
nmemb = r / size;
|
||||
goto loop;
|
||||
}
|
||||
/* qsort(pn - r, r / size, size, comper);*/
|
||||
}
|
||||
|
||||
#if 0
|
||||
|
||||
/*
|
||||
* Below is an example of a naive qsort implementation
|
||||
*/
|
||||
|
||||
#define swap(a,b,size) \
|
||||
do { \
|
||||
qse_size_t i = 0; \
|
||||
qse_byte_t* p1 = (a); \
|
||||
qse_byte_t* p2 = (b); \
|
||||
for (i = 0; i < size; i++) { \
|
||||
qse_byte_t t = *p1; \
|
||||
*p1 = *p2; \
|
||||
*p2 = t; \
|
||||
p1++; p2++; \
|
||||
} \
|
||||
} while (0)
|
||||
|
||||
#define REF(x,i) (&((x)[(i)*size]))
|
||||
|
||||
void qse_qsort (void* base, qse_size_t nmemb, qse_size_t size, void* arg,
|
||||
int (*compar)(const void*, const void*, void*))
|
||||
{
|
||||
qse_size_t pivot, start, end;
|
||||
qse_byte_t* p = (qse_byte_t*)base;
|
||||
|
||||
if (nmemb <= 1) return;
|
||||
if (nmemb == 2) {
|
||||
if (compar(REF(p,0), REF(p,1), arg) > 0)
|
||||
swap (REF(p,0), REF(p,1), size);
|
||||
return;
|
||||
}
|
||||
|
||||
pivot = nmemb >> 1; /* choose the middle as the pivot index */
|
||||
swap (REF(p,pivot), REF(p,nmemb-1), size); /* swap the pivot with the last item */
|
||||
|
||||
start = 0; end = nmemb - 2;
|
||||
|
||||
while (1) {
|
||||
/* look for the larger value than pivot */
|
||||
while (start <= end &&
|
||||
compar(REF(p,start), REF(p,nmemb-1), arg) <= 0) start++;
|
||||
|
||||
/* look for the less value than pivot. */
|
||||
while (end > start &&
|
||||
compar(REF(p,end), REF(p,nmemb-1), arg) >= 0) end--;
|
||||
|
||||
if (start >= end) break; /* no more to swap */
|
||||
swap (REF(p,start), REF(p,end), size);
|
||||
start++; end--;
|
||||
}
|
||||
|
||||
swap (REF(p,nmemb-1), REF(p,start), size);
|
||||
pivot = start; /* adjust the pivot index */
|
||||
|
||||
qse_qsort (REF(p,0), pivot, size, arg, compar);
|
||||
qse_qsort (REF(p,pivot+1), nmemb - pivot - 1, size, arg, compar);
|
||||
}
|
||||
|
||||
/*
|
||||
* For easier understanding, see the following
|
||||
*/
|
||||
|
||||
#define swap(a, b) do { a ^= b; b ^= a; a ^= b; } while (0)
|
||||
|
||||
void qsort (int* x, size_t n)
|
||||
{
|
||||
size_t index, start, end;
|
||||
int pivot;
|
||||
|
||||
if (n <= 1) return;
|
||||
if (n == 2) {
|
||||
if (x[0] > x[1]) swap (x[0], x[1]);
|
||||
return;
|
||||
}
|
||||
|
||||
index = n / 2; /* choose the middle as the pivot index */
|
||||
pivot = x[index]; /* store the pivot value */
|
||||
swap (x[index], x[n - 1]); /* swap the pivot with the last item */
|
||||
|
||||
start = 0; end = n - 2;
|
||||
while (1) {
|
||||
/* look for the larger value than pivot */
|
||||
while (start <= end && x[start] <= pivot) start++;
|
||||
|
||||
/* look for the less value than pivot. */
|
||||
while (end > start && x[end] >= pivot) end--;
|
||||
|
||||
if (start >= end) {
|
||||
/* less values all on the left,
|
||||
* larger values all on the right
|
||||
*/
|
||||
break;
|
||||
}
|
||||
|
||||
swap (x[start], x[end]);
|
||||
start++; end--;
|
||||
}
|
||||
|
||||
x[n - 1] = x[start]; /* restore the pivot value */
|
||||
x[start] = pivot;
|
||||
index = start; /* adjust the pivot index */
|
||||
|
||||
qsort (x, index);
|
||||
qsort (&x[index + 1], n - index - 1);
|
||||
}
|
||||
|
||||
#endif
|
||||
Loading…
Reference in New Issue
Block a user